基于支路循环理论的双环路自然循环系统海洋条件下流动特性分析

Flow Characteristics Analysis of Natural Circulation System with Double Loop Under Ocean Condition Based on Branch Circulation Theory

针对单相双环路自然循环系统,采用支路循环理论,建立分析模型。通过对质量、动量及能量守恒关系的推导,得到倾斜、摇摆以及起伏等海洋条件下的双环路系统自然循环流量的无量纲表达式,并与相关文献的实验结果相比对,结果吻合较好。分析讨论倾斜、摇摆与起伏等海洋条件对自然循环流量的影响,并给出摇摆振幅与摇摆周期的关系。研究表明,倾斜时回路宽度与倾斜前冷热源高度差的比值对双环路自然循环系统的流量分布有较大影响;在不同摇摆条件下,如果引起自然循环流量的振幅相同,则其最大摇摆角加速度必然相同,起伏运动时,加速度与重力加速度的比值较小,则对自然循环流量的影响可以不予考虑。

For the single-phase double branch natural circulation system,we use the branch cycle theory to establish a dimensionless analysis.Through the derivation of the conservation relationship between mass,momentum and energy,we obtain the dimensionless expression of the natural flow of the double-loop system under ocean conditions such as tilt,sway and undulation,and compare it with the experimental results of related literatures.We analyze the effects of ocean conditions such as tilt,sway and undulation on the natural circulation and give the relationship between the sway amplitude and the sway period.The research shows that the ratio of the loop width at the time of tilting to the height difference of the cold heat source before tilting has a great influence on the flow distribution of the natural circulation system of the double loop.Under different rocking conditions,if the amplitude of the natural circulation flow is the same,the maximum yaw acceleration to gravity acceleration,the influence on the natural circulation flow can be ignored.